title: Birds exploit herbivore-induced plant volatiles to locate herbivorous prey.
abstract: Arthropod herbivory induces plant volatiles that can be used by natural enemies of the herbivores to find their prey. This has been studied mainly for arthropods that prey upon or parasitise herbivorous arthropods but rarely for insectivorous birds, one of the main groups of predators of herbivorous insects such as lepidopteran larvae. Here, we show that great tits (Parus major) discriminate between caterpillar-infested and uninfested trees. Birds were attracted to infested trees, even when they could not see the larvae or their feeding damage. We furthermore show that infested and uninfested trees differ in volatile emissions and visual characteristics. Finally, we show, for the first time, that birds smell which tree is infested with their prey based on differences in volatile profiles emitted by infested and uninfested trees. Volatiles emitted by plants in response to herbivory by lepidopteran larvae thus not only attract predatory insects but also vertebrate predators.
authors.affiliation: Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700 AB, Wageningen, The Netherlands; Departamento de Ecología Funcional y Evolutiva, Estación Experimental de Zonas Áridas (CSIC), Ctra, de Sacramento s/n. E-04120, La Cañada de San Urbano, Almería, Spain.
authors.forename: Luisa
authors.initials: L
authors.lastname: Amo
authors.forename: Jeroen J
authors.initials: JJ
authors.lastname: Jansen
authors.forename: Nicole M
authors.initials: NM
authors.lastname: van Dam
authors.forename: Marcel
authors.initials: M
authors.lastname: Dicke
authors.forename: Marcel E
authors.initials: ME
authors.lastname: Visser
mesh_terms: D000818:Animals; D060434:Herbivory; D007814:Larva / Q000502:physiology; D027845:Malus / Q000378:metabolism*; D009036:Moths / Q000502:physiology*; D046109:Passeriformes / Q000502:physiology*; D012903:Smell; D055549:Volatile Organic Compounds / Q000737:chemistry / Q000378:metabolism*
chemical_list: D055549:Volatile Organic Compounds
keywords: Apple trees; Parus major; avian olfaction; foraging; induced indirect plant defence; insect herbivores; insectivorous birds; multitrophic interactions